The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines (ICEs) combust an air and fuel mixture within cylinders to drive pistons, which produces drive torque. Air flow into the ICE is regulated via a throttle. More specifically, the throttle adjusts throttle area, which adjusts air flow into the ICE. A fuel control system adjusts the rate that fuel is injected to provide a desired air/fuel mixture to the cylinders and/or to achieve a desired torque output. Increasing the amount of air and fuel provided to the cylinders increases the torque output of the ICE. A turbocharger may be used, for example, to increase air flow into the cylinders of the ICE.
Engine systems include components that are cooled and/or lubricated via respective fluids, such as oil, water, glycol-based coolants, etc. The components may include pistons, piston rod bearings, camshaft and crankshaft bearings, turbocharger compressor and turbine bearings, etc. During certain conditions, high engine loads may be requested when an inadequate supply and/or viscosity of a cooling/lubricating fluid is present. This can result in damage to engine components. For example, cooling/lubricating fluids supplied from an ICE to a turbocharger may drain out of the turbocharger when the ICE is shutdown. The cooling/lubricating fluids are pumped to the turbocharger when the ICE is restarted. Time for the fluids to reach components of the turbocharger can depend on sizes of fluid feed lines and/or orifices. During a cold start of the ICE, high turbocharger loads may be introduced prior to an adequate supply of the cooling/lubricating fluids reaching bearings of the turbocharger. This can cause damage to turbocharger components.
As another example, during a cold start of an engine if there is an inadequate amount of oil supplied to cylinders of an engine, piston scuff can result. Piston scuff refers to rubbing of a piston against a cylinder wall due to inadequate clearances between the piston and the cylinder wall. Clearances between a piston and a cylinder wall can vary depending on temperatures and materials of the piston and the cylinder wall. As an example, a piston may be formed of aluminum and a cylinder wall may be formed of iron, which heats and expands at different rates then aluminum.
As yet another example, during high temperature conditions, viscosity of cooling/lubricating fluids can decrease (i.e. thin-out). This reduces cooling and lubricating affects on respective engine components, which can result in damage to the engine components.